Bridge Research On Key Construction Control Technologies Of Continuous Beam Swivel Bridge

With the development of China’s transportation industry,the horizontal rotation construction technology has been widely used.Due to the influence of uncertain factors such as environmental conditions and construction experience,there are often problems such as inactive rotation,inaccurate rotation,and inconsistency between the actual state of the bridge and the theory in the rotation construction process.Therefore,on the one hand,in order to ensure the safety and stability of the bridge structure and ensure the smooth rotation of the bridge,it is necessary to carry out theoretical analysis and simulation calculation of the construction process of the bridge,and then obtain the theoretical state value of the bridge structure at all stages of construction,which provides the basis for the monitoring of the structural internal force,linear and rotational state of the bridge in the construction process.On the other hand,the existing normative algorithm for the surface stress of the spherical hinge and the corresponding rotational parameters is quite different from the application in practical engineering.Therefore,the accurate calculation of the surface stress distribution and related parameters of the rotational spherical hinge needs to be further improved.In this paper,the super-large swivel bridge of Ningxiang Railway Station is taken as the research background.1.Firstly,the finite element analysis model of the main beam and rotation system of the bridge is established,and the deformation and stress of each section of the bridge in the construction process are analyzed.2.The stress and deflection of the key section of the main beam are monitored on site,and the measured results are compared with the theoretical data.3.The key rotation parameters in the rotation construction of the bridge are measured through the beam weighing experiment;4.Based on different theoretical methods,the stress distribution law of spherical hinge is studied,and the stress distribution model of spherical hinge in the form of vertical parabola is proposed.The calculation formulas of vertical and horizontal friction torque of rotational system are established,and then the parameters such as friction coefficient and traction force are solved,and the calculated values are compared with the field measured values.5.The bridge rotation process is divided into acceleration,uniform speed and deceleration stages,and the speed control formula of each process is established.The error between the theoretical value and the actual value in the trial rotation process is corrected by the least square method.The results show that:1.The measured values of deflection and stress at the construction stage of the main beam are consistent with the theoretical values,and the error is within the allowable range;2.When the position of the prestressed reinforcement of the main beam changes and the system changes,the stress value and deflection value change significantly;3.Compared with the standard algorithm,more accurate results will be obtained when the vertical parabolic spherical hinge stress distribution model is used to calculate the key rotation parameters;4.For large-tonnage rotating bridges,the acceleration and deceleration processes are very rapid and negligible.Before the formal rotation of the bridge,the error correction of the rotation parameters can better control the rotation time of the bridge and ensure the accurate closure of the bridge.